1. Field of the Invention
The present invention relates to a tilt device for a marine propulsion unit and a method for assembling the tilt device.
2. Description of the Prior Art
Examples of tilt devices for marine propulsion devices include a tilt device of an outboard motor. The outboard motor includes a propulsion unit comprising a propeller and an engine, supported axially by a swivel bracket such that the horizontal swinging movement is allowed, with the swivel bracket supported by a clamp bracket such that the vertical tilting movement is allowed, with the clamp bracket gripping the hull. A tilt device is provided between the clamp bracket and the swivel bracket such that the motive power is generated by the telescopic motion of a hydraulic cylinder of the tilt device. The propulsion unit and the swivel bracket are tilted vertically with respect to the clamp bracket so as to allow the tilt operation or the trim operation of the propulsion unit.
In addition to the above-mentioned hydraulic cylinder device, the tilt device further comprises a tank device for storing a hydraulic fluid and a pump device for supplying and exhausting the hydraulic fluid in the tank device into the hydraulic cylinder device so as to operate the hydraulic cylinder device telescopically.
As an example of a tilt device, Japanese Utility Model Application Publication (JP-Y) No. 8-6715 discloses a cylinder of a cylinder device, a valve block, which stores various kinds of valves of a pump device, and a tank case of a tank device integrally cast-molded.
However, the above-mentioned tilt device having the cylinder, the valve block, and the tank case formed as one piece requires a large casting mold and leads to the cost increase. Besides, since the cylinder is cast-molded, it becomes thick so that the tilt device becomes larger. Furthermore, since the cylinder is cast-molded, the production time is increased, such as the mirror processing of the inside of the cylinder, and a long boring processing for forming a channel in the molded cylinder.